AMADEus Seminar - Prof. Eduard Llobet - Friday 4 July 2014, 11:00 am - Aérocampus, Latresne

Bottom up integration of metal oxide nanomaterials in MEMS for gas/bio sensing applications

Abstract:

The commercial exploitation of nanomaterials in real-world devices is a major driver in nanoscience and nanotechnology requiring synthesis techniques that are compatible with manufacturing processes. Recently we have demonstrated a new catalyst free, (relatively) low temperature single-step aerosol assisted chemical vapor deposition method to grow metal oxide nanowires functionalized with Au, Pt, CuO, Pd or Au and Pt nanoparticles, achieved by tuning the degree of homogeneous and heterogeneous gas-phase reactions of both metal and metal oxide. Also, we have achieved the growth of mixed oxide nanorods employing smart anodization techniques. These methods have then been used to create a matrix of MEMS based gas sensors with different sensing elements, i.e. non-functionalized and functionalized metal oxide with different metal/ metal oxide nanoparticles, where the unique characteristics of the individual nanomaterials have been exploited to differentiate and quantify analytes such as EtOH, H2, CO, C6H6, NO2. The high surface-to-volume ratio and large accessible surface of nanoscaled metal oxides allows the use of very small amounts of these materials as the active sensing layer, in turn enabling microsensor (MEMS) platforms to be utilized for devices where bulk materials do not give the sensitivity required. Miniaturization of devices reduces material consumption in device manufacture and reduces power consumption in device operation, and miniaturization of sensors also offers faster response times and lower detection limits than traditional ceramic sensors. Here we will review the main characteristics of the growth of nanostructures and their bottom-up integration in sensor transducer substrates. This is to be followed by discussions on the characterization of such nanomaterials and on the study of their gas sensing properties. Finally, new results on the use of such devices for bio-sensing will be presented as well.